Changeset 628

Timestamp:

03/26/06 12:51:55 (7 years ago)

Author:

ahu

Message:

move negcache to boost::multi_index, make sure it gets pruned a bit faster. Also, and this is controversial, cap SOA negative caching to 3600 seconds.
This is done for two reasons: 1) the cache grows HUGE otherwise 2) I'm pretty sure anything >3600 seconds will annoy people
a lot.

Location:

trunk/pdns/pdns

Files:

• mtasker.cc (modified) (1 diff)
• pdns_recursor.cc (modified) (2 diffs)
• rec_channel_rec.cc (modified) (2 diffs)
• syncres.cc (modified) (4 diffs)
• syncres.hh (modified) (2 diffs)

trunk/pdns/pdns/mtasker.cc

@@ -1 +1 @@
 /*
     PowerDNS Versatile Database Driven Nameserver
-    Copyright (C) 2002 - 2005  PowerDNS.COM BV
+    Copyright (C) 2002 - 2006  PowerDNS.COM BV
 
     This program is free software; you can redistribute it and/or modify
-    it under the terms of the GNU General Public License as published by
-    the Free Software Foundation; either version 2 of the License, or
-    (at your option) any later version.
+    it under the terms of the GNU General Public License version 2 as 
+    published by the Free Software Foundation
 
     This program is distributed in the hope that it will be useful,

trunk/pdns/pdns/pdns_recursor.cc

@@ -49 +49 @@
 #include "rec_channel.hh"
 
-// using namespace boost;
+using namespace boost;
 
 #ifdef __FreeBSD__           // see cvstrac ticket #26
@@ -546 +546 @@
     RC.doPrune();
     int pruned=0;
-    for(SyncRes::negcache_t::iterator i = SyncRes::s_negcache.begin(); i != SyncRes::s_negcache.end();) 
-      if(i->second.ttd < now.tv_sec) {
-        SyncRes::s_negcache.erase(i++);
-        pruned++;
-      }
-      else
-        ++i;
+    
+    typedef SyncRes::negcache_t::nth_index<1>::type negcache_by_ttd_index_t;
+    negcache_by_ttd_index_t& ttdindex=boost::multi_index::get<1>(SyncRes::s_negcache);
+
+    negcache_by_ttd_index_t::iterator i=ttdindex.lower_bound(now.tv_sec);
+    ttdindex.erase(ttdindex.begin(), i);
 
     time_t limit=now.tv_sec-300;

trunk/pdns/pdns/rec_channel_rec.cc

@@ -112 +112 @@
   addGetStat("cache-misses", &RC.cacheMisses);
 
-  addGetStat("cache-entries", bind(&MemRecursorCache::size, ref(RC)));
+  addGetStat("cache-entries", boost::bind(&MemRecursorCache::size, ref(RC)));
   addGetStat("servfail-answers", &g_stats.servFails);
   addGetStat("nxdomain-answers", &g_stats.nxDomains);
@@ -126 +126 @@
 
   addGetStat("all-questions", &qcounter);
-  addGetStat("negcache-entries", bind(&SyncRes::negcache_t::size, ref(SyncRes::s_negcache)));
-  addGetStat("throttle-entries", bind(&SyncRes::throttle_t::size, ref(SyncRes::s_throttle)));
-  addGetStat("nsspeeds-entries", bind(&SyncRes::nsspeeds_t::size, ref(SyncRes::s_nsSpeeds)));
+  addGetStat("negcache-entries", boost::bind(&SyncRes::negcache_t::size, ref(SyncRes::s_negcache)));
+  addGetStat("throttle-entries", boost::bind(&SyncRes::throttle_t::size, ref(SyncRes::s_throttle)));
+  addGetStat("nsspeeds-entries", boost::bind(&SyncRes::nsspeeds_t::size, ref(SyncRes::s_nsSpeeds)));
 
-  addGetStat("concurrent-queries", bind(&MTasker<PacketID,string>::numProcesses, ref(MT)));
+  addGetStat("concurrent-queries", boost::bind(&MTasker<PacketID,string>::numProcesses, ref(MT)));
   addGetStat("outgoing-timeouts", &SyncRes::s_outgoingtimeouts);
   addGetStat("tcp-outqueries", &SyncRes::s_tcpoutqueries);

trunk/pdns/pdns/syncres.cc

@@ -249 +249 @@
   uint32_t sttl=0;
 
-  if(s_negcache.count(toLower(qname))) {
+  negcache_t::iterator ni=s_negcache.find(toLower(qname));
+  if(ni!=s_negcache.end()) {
+    cerr<<"found something\n";
     res=0;
-    negcache_t::const_iterator ni=s_negcache.find(toLower(qname));
-    if(d_now.tv_sec < ni->second.ttd) {
-      sttl=ni->second.ttd - d_now.tv_sec;
+    if((uint32_t)d_now.tv_sec < ni->d_ttd) {
+      sttl=ni->d_ttd - d_now.tv_sec;
       LOG<<prefix<<qname<<": Entire record '"<<toLower(qname)<<"', is negatively cached for another "<<sttl<<" seconds"<<endl;
       res=RCode::NXDomain; 
       giveNegative=true;
-      sqname=ni->second.name;
+      sqname=ni->d_qname;
       sqt="SOA";
     }
     else {
       LOG<<prefix<<qname<<": Entire record '"<<toLower(qname)<<"' was negatively cached, but entry expired"<<endl;
-      s_negcache.erase(toLower(qname));
+      s_negcache.erase(ni);
     }
   }
@@ -271 +272 @@
 
     res=0;
-    negcache_t::const_iterator ni=s_negcache.find(tuple);
+    ni=s_negcache.find(tuple);
     if(ni!=s_negcache.end()) {
-      if(d_now.tv_sec < ni->second.ttd) {
-        sttl=ni->second.ttd - d_now.tv_sec;
+      if((uint32_t)d_now.tv_sec < ni->d_ttd) {
+        sttl=ni->d_ttd - d_now.tv_sec;
         LOG<<prefix<<qname<<": "<<qtype.getName()<<" is negatively cached for another "<<sttl<<" seconds"<<endl;
         res=RCode::NoError; // only this record doesn't exist
         giveNegative=true;
-        sqname=ni->second.name;
+        sqname=ni->d_qname;
         sqt="SOA";
       }
       else {
         LOG<<prefix<<qname<<": "<<qtype.getName()<<" was negatively cached, but entry expired"<<endl;
-        s_negcache.erase(toLower(tuple));
+        s_negcache.erase(ni);
       }
     }
@@ -529 +530 @@
 
           NegCacheEntry ne;
-          ne.name=i->qname;
-          ne.ttd=d_now.tv_sec + i->ttl;
-          s_negcache[toLower(qname)]=ne;
+
+          ne.d_qname=i->qname;
+          ne.d_ttd=d_now.tv_sec + min(i->ttl, 3600U); // controversial
+          ne.d_name=toLower(qname);
+          s_negcache.insert(ne);
           negindic=true;
         }
@@ -568 +571 @@
           
           NegCacheEntry ne;
-          ne.name=i->qname;
-          ne.ttd=d_now.tv_sec + i->ttl;
-          s_negcache[toLower(qname)+"|"+qtype.getName()]=ne;
+          ne.d_qname=i->qname;
+          ne.d_ttd=d_now.tv_sec + min(3600U,i->ttl);
+          ne.d_name=toLower(qname)+"|"+qtype.getName();
+          s_negcache.insert(ne);
           negindic=true;
         }

trunk/pdns/pdns/syncres.hh

@@ -26 +26 @@
 struct NegCacheEntry
 {
-  string name;
-  time_t ttd;
+  string d_qname;
+  string d_name;
+  uint32_t d_ttd;
 };
 
@@ -241 +242 @@
   unsigned int d_throttledqueries;
   unsigned int d_timeouts;
-  typedef map<string,NegCacheEntry> negcache_t;
+  //  typedef map<string,NegCacheEntry> negcache_t;
+
+  typedef multi_index_container <
+    NegCacheEntry,
+    indexed_by <
+       ordered_unique<
+           member<NegCacheEntry, string, &NegCacheEntry::d_name>
+       >,
+       ordered_non_unique<
+           member<NegCacheEntry, uint32_t, &NegCacheEntry::d_ttd>
+       >
+    >
+  >negcache_t;
   static negcache_t s_negcache;